The present invention relates to a structure of a heat exchanger core that does not use a header plate.
There is known a tank coupling structure of a heat exchanger without a header plate described in Japanese Patent Laid-open No. 2014-55711. In the structure, expansion parts are formed at both end portions on an opening side of a pair of plates formed into a groove shape, and the plates are superimposed in a reverse direction to configure a flat tube. Then, respective flat tubes are superimposed at the expansion parts to assemble a core of a heat exchanger without a header plate. Then, a casing is fitted onto the outer periphery of the core. Then, in a high temperature furnace, the core is integrally brazed and a tank is fitted onto both ends of the core to thereby complete a heat exchanger.
At this time, a stacked body 8 obtained by assembling the flat tubes 7 is formed as in FIG. 20(B), and, onto the outer periphery of the stacked body 8, a casing 9 is fitted as in FIG. 20(A). Then, between an opening end of the stacked body 8 and the casing 9, an annular groove is formed, and an edge part of a tank 24 is caulked and fixed thereto via a packing 23.
That is, as shown in FIG. 21, the casing 9 is fitted onto the outer periphery of the stacked body 8 including an assembly of the flat tubes 7, and, in the inside of the casing 9, a tip edge of the stacked body 8 impinges on the rear end of a bracket 31. Then, between a step part of the bracket 31 and the casing 9, a groove part is formed, into which the packing 23 is fitted, and a tip of the casing 9 is caulked to couple the tank 24.